NASA SkyWatch
is a web based Java application (or applet) that can be used to generate
highly accurate acquisition information for an earth orbiting satellite.
Each time the satellite appears above the horizon for a specified ground
site, NASA SkyWatch will compute such information as range, azimuth,
and elevation. Also, NASA SkyWatch
will determine if any of the "pass" will be visible. Making a "sighting"
of a satellite is great fun and an excellent learning experience for
both children and adults.

NASA SkyWatch
is primarily an application to determine acquisition information - or
when a satellite will be above the horizon at a given place and time.
Once the acquisition data has been determined, a sighting is also possible
if 4 conditions have been met:

The satellite must be above
the horizon

The observer must be in
darkness (sun below the observer's horizon)

The satellite must be in
sunlight (sun above the satellite's horizon)

The correct side of the
satellite must be lit

NASA SkyWatch
can be used for any Earth orbiting satellite - not just for the International Space Station. NASA SkyWatch regulary monitors
major NASA satellites that may be of interest. Currently, the list of
satellites that can be selected include the following:

Every effort has been made
to develop NASA SkyWatch
as a simple to use yet powerful application to provide highly accurate
and detailed information. These help pages are being provided to guide
your way through NASA SkyWatch
the first few times it is used. You will find that once you learn NASA
SkyWatch's input requirements,
sighting information is just a few minutes away.

The NASA SkyWatch
input and results are divided into 7 sections - 4 for input and 3 for
output. These sections are in the form of "tabs" in the upper left of
the user interface. All that is required to jump from section to section
is to click on the tab. In these help pages, clicking on the tab will
take you to a detailed help page for that particular section. Once inside
the detailed help page, clicking on an input or output will display
more information about that item.

System Requirements:

It is recommended that the
user be running a Pentium class (or equivalent) computer system. Slower
systems will run NASA SkyWatch
but may take considerable more time to complete. The applet is not resolution
independent and was developed for resolution of 800x600 on a Windows
based computer system. Other resolutions and operating systems will
work but some scrolling by the user may be required if less than 800x600.
Resolutions greater than 800x600 will also work but may not be readable
due the small character size.

Please note that due to the
complexity of this applet, you will need the Microsoft
Internet Explorer version 4.0 or later. You can also use Netscape
Navigator version 4.06 or later. Macintosh systems require Internet
Explorer version 4.5 or later, plus the Macintosh OS Runtime Environment
for Java version 2.1 or later. Windows users require the Java version 1.4.2_04.
If you need to acquire these browsers, please do so before attempting to
run NASA SkyWatch.